"You could look a bit more excited Will. #TheVoice," one viewer wrote online.

"Will.i.am looks bored #thevoiceuk," added another.

A third agreed: "Will.I.am as bored of The Voice as I am? He's sat tapping away on his phone & iPad."

Will revealed recently he had originally been 'told off' for his live tweeting during the show back in the first series, but now claims that producers encourage him.

"The first year I got in trouble. They said, 'People might think you look like you're not engaged'" Will explained. "I was like, 'In the future, news reporters are going to be tweeting during the show... It may look weird now because the show isn't formatted for that behaviour, but if it was, it would be great because you'd be telling everybody to tweet and there would be a camera on the desk."

He added to DigitalSpy: "So that was the first year.

"And the second year they were like, 'Are you going to tweet?' Because it adds to a better show for the folks who are actually tweeting and watching the show."